I think you’re right, but my take is that the user freedom bit is a regulatory overreach. Couldn’t Apple literally turn off the App Store tomorrow, or replace everything with first party applications? There’s no law saying they have to support all these developers, though the DMA may require this indirectly. It feels like a slippery slope to “you need to be able to run Android on your iPhone hardware” or something like that.
It just seems really far fetched to me if you were to apply this logic to other industries- eg “movie theaters must let you play any movie, not just the movies they want!” Or “movie theaters must allow you to bring your own popcorn or allow competing concessions vendors!”
What I think is within regulatory oversight is the fees people charge within certain jurisdictions, because governments should regulate commerce. Similar to how they regulate bank fees, real estate transactions, VAT, etc. They could set a maximum, prevent charging fees for free software, or all sorts of other things that would help developers and consumers without forcing Apple to support weird 3rd party app distributors.